package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author jie
 * @version 1.0 2024-12-31
 */
@Component
public class RedisIdWorker {
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    private static final short COUNT_BITS = 32;

    private final StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix) {
        // 1. 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        // 2. 生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        // 3. 拼接并返回
        if (count != null) {
            return timestamp << COUNT_BITS | count;
        } else {
            return timestamp << COUNT_BITS;
        }
    }
}
